4 files changed, 31 insertions, 3 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 88f15631701a..aeaf6dff6e05 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -461,6 +461,33 @@ ieee80211_chandef_rate_flags(struct cfg80211_chan_def *chandef)
 }
 
 /**
+ * ieee80211_chandef_max_power - maximum transmission power for the chandef
+ *
+ * In some regulations, the transmit power may depend on the configured channel
+ * bandwidth which may be defined as dBm/MHz. This function returns the actual
+ * max_power for non-standard (20 MHz) channels.
+ *
+ * @chandef: channel definition for the channel
+ *
+ * Returns: maximum allowed transmission power in dBm for the chandef
+ */
+static inline int
+ieee80211_chandef_max_power(struct cfg80211_chan_def *chandef)
+{
+        switch (chandef->width) {
+        case NL80211_CHAN_WIDTH_5:
+                return min(chandef->chan->max_reg_power - 6,
+                           chandef->chan->max_power);
+        case NL80211_CHAN_WIDTH_10:
+                return min(chandef->chan->max_reg_power - 3,
+                           chandef->chan->max_power);
+        default:
+                break;
+        }
+        return chandef->chan->max_power;
+}
+
+/**
  * enum survey_info_flags - survey information flags
  *
  * @SURVEY_INFO_NOISE_DBM: noise (in dBm) was filled in
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index cc117591f678..4c41c11958c8 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -54,7 +54,7 @@ bool __ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)
                 return false;
         }
 
-        power = chanctx_conf->def.chan->max_power;
+        power = ieee80211_chandef_max_power(&chanctx_conf->def);
         rcu_read_unlock();
 
         if (sdata->user_power_level != IEEE80211_UNSET_POWER_LEVEL)
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 091088ac7890..6da98c77496b 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -151,7 +151,7 @@ static u32 ieee80211_hw_conf_chan(struct ieee80211_local *local)
                 changed |= IEEE80211_CONF_CHANGE_SMPS;
         }
 
-        power = chandef.chan->max_power;
+        power = ieee80211_chandef_max_power(&chandef);
 
         rcu_read_lock();
         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index f7552c2b74eb..211246b46819 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -747,7 +747,8 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
                 *pos++ = WLAN_EID_PWR_CAPABILITY;
                 *pos++ = 2;
                 *pos++ = 0; /* min tx power */
-                *pos++ = chan->max_power; /* max tx power */
+                 /* max tx power */
+                *pos++ = ieee80211_chandef_max_power(&chanctx_conf->def);
 
                 /* 2. supported channels */
                 /* TODO: get this in reg domain format */